Preliminary evidence that lectins in infant soy formula apparently bind bovine milk exosomes and prevent their absorption in healthy adults

Ezra Mutai, Alice Kah Hui Ngu, Janos Zempleni

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Background: Milk exosomes and their microRNA (miR) cargos are bioavailable. The content of exosomes and miRs is negligible in infant formulas compared to human milk, and dietary depletion of exosomes led to changes in bacterial communities and impaired gut health in juvenile mice. Adverse effects of formula feeding may be compounded by using soy formulas due to exosome binding by abundant lectins in that matrix. The purpose of this study was to assess the bioavailability of milk exosomes and their miR cargos added to soy formula in adults, as well as the potential role of soy lectins in exosome bioavailability. Methods: Eleven healthy adults (6 men, 5 women) enrolled in this randomized crossover study. Participants consumed 1.0 l of soy formula without (SF) or with (SFE) bovine milk exosomes added. Concentration-time curves of six plasma miRs were analyzed using reverse transcription quantitative PCR. Lectin affinity chromatography was used to assess the binding of exosomes by soy lectins. Data were analyzed by using paired t test. P < 0.05 was considered statistically significant. Results: Consumption of SF and SFE did not elicit postprandial increases in plasma miRs. Approximately 39% of bovine milk exosome particles were retained by lectin columns. Conclusions: We conclude that fortification of soy formulas with milk exosomes, in the absence of removing lectins, is not a viable strategy for delivering bioavailable exosomes and their miR cargos. Lectins in soy formulas bind glycoprotein on the surfaces of milk exosomes, thereby preventing exosome absorption. Trial registration: ISRCTN registry ID: 16329971. Retrospectively registered on February 7th, 2019.

Original languageEnglish (US)
Article number7
JournalBMC Nutrition
Issue number1
StatePublished - Dec 2022
Externally publishedYes


  • Bioavailability
  • Bovine milk exosomes
  • Human
  • Infant soy formula
  • Lectins
  • Milk
  • microRNA

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health


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